Grammar rules

Use commas to set apart a noun or phrase that explains or identifies something. 

Use commas to set apart INTERRUPTERS, words or expressions that break the flow of thought in a sentence. 

The winners of course must be present 

Many students if you ask me did a good job on their research projects

Use a comma to separate TRANSITIONS from the sentence (such as first, next, finally, also, later in the story, in addition, etc.).

 Finally I’ll be old enough to get my driver’s permit 

Therefore I believe young people should not smoke

Yes I agree with your answer

Well would anyone like to go see a movie

semicolons are not interchangeable with commas or periods. Instead, they are somewhere in between: stronger than a comma but not quite as divisive as a period.

The most common use of the semicolon is to join two independent clauses without using a conjunction like and.

Link Ideas with a Conjunction